Second nozzle spinning machine is rolling them out in China too
09 December 2013
In short, DMC now has two spinning machines to manufacture propeller nozzles in the revolutionary way, with basically one single weld only! Their performance? Super.
The longer version is that Damen Marine Components has just put its second spinning machine into service, in China, following the introduction of this innovative technique in Gdansk, Poland, early 2012. 18 months on, it can safely be said that this is both the new cutting edge standard in nozzle manufacturing and proven technology at the same time. DMC’s second spinning machine, in Jiang Yin has already delivered its first series of nozzle inner rings since November 2013. So the technique with which DMC has revolutionized nozzle production, is now up and running at both of our plants, ensuring rapid delivery – or shortest lead times to be precise - at either end of the globe. Having one single weld only, the nozzles are de facto one seam short of seamless.
“The nozzles can be manufactured somewhat lighter and have a smoother inside. Traditional propeller nozzle manufacturing requires a minimum ten up to thirty or even more welds at the inside of the nozzle, depending on size. Our new technique basically requires one weld only and in addition gives a much smoother surface. What could be better than that?”, Mr. Cees Bons, Senior Production Manager with Damen Marine Components in China hailed about the novel spinning machine that has just come on stream in China.
The principle pivots around (literally) transforming a steel tube into a bell-shaped nozzle inner ring through mechanical cold moulding. The technique most resembles the shaping of an open-ended vase on the potter’s wheel.
The spinning machine starts with a tube that has been plate rolled and welded – hence the one, single weld only - on the spot in DMC’s manufacturing halls. A calm and cautious process, it still far outspeeds the traditional patchwork-style welding of the nozzle inner ring from many steel parts, especially when the rings are big. The new spinning machine in China can go up to 7 metres in diameter – starting from 1 metre. “We are able to make an extension on our spinning table up to a diameter of ten meters”, Cees Bons added.
“The machine in Jiang Yin, China can handle carbon steel to a maximum of 36 millimeters thickness, and stainless steel and Duplex to a maximum of 25 millimeters. Some clients want a stainless steel ring only in the nozzle’s central cavitation zone, with a carbon steel in- and outlet. This would still involve two welds only! It still is almost seamless”, Mr. Steef Staal, DMC’s Managing Director noted. He added that the traditional production method by means of the welding of multiple steel parts will continue to be used, if the spinning machines in China or Poland cannot accommodate specific sizes or specials.
New China HQ
DMC’s new spinning machine was assembled in China by Korean engineers under the supervision of Cees Bons, assisted by some members of the Jiang Yin crew. It is a pioneer in more ways than one, being the marine components manufacturer’s first operation in Jiang Yin, near the Yangtze River. A production hall is temporarily being rented there ahead of DMC’s removal, lock stock and barrel, from Suzhou. “As our 5,000 square metre plant in Suzhou had become too small – also following our expanding manufacturing of winches – we have opted to move entirely”, Steef Staal said. “Our new 12,000 square metre complex is currently being built and by late 2014 we plan to have moved-in completely, including our show-piece propeller nozzle spinning machine.”